	public function executeCompare(sfWebRequest $request)
	{
		$id = $request->getParameter('<?php echo isset($this->params['route_column']) ? $this->params['route_column'] : 'id' ?>');
		$version = $request->getParameter('version');

		$table = Doctrine_Core::getTable('<?php echo $this->getModelClass() ?>');

		$this->current = $table->getCurrentVersion($id);
		$this->previous = $table->getVersion($this->current->id, $version);

		$this->forward404Unless($this->previous);
	}
